Compressors are used in sewage aeration applications to deliver compressed air to sewage for treatment. The compressors run continuously (e.g. 24 hours a day, seven days a week) and thus may be need to be replaced at frequent intervals.
Two types of compressors are commonly used. One is a rotary vane compressor and the other type is a double diaphragm linear compressor. Both types are known in the art. Each type of compressor includes an end construction with an inlet and an outlet port or connection unique to that type of compressor. For example, double diaphragm linear compressors include simple tube connections which may be hollow sleeves having cylindrical shapes with perhaps ring-like retaining barbs for receiving tubes. Rotary vane compressors use threaded connections of the plumbing or National Pipe Thread type for receiving threaded members, such as pipes.
In the aeration application it is sometimes desirable to substitute a rotary vane compressor with threaded connections for a double diaphragm linear compressor which uses tube-type connections. But the substitution is impeded by the mismatch between the tube-type connection and the threaded connection. Thus the ability to retrofit compressors in the field is impeded.
Rotary vane compressors typically include a rotor with vanes which rotates within a cylindrical housing. By that rotation air is drawn into the compressor, compressed and then exits as compressed air. The entry and exit is via the ports/connections discussed above.
Such rotary vane compressors are available from Gast Manufacturing, Inc., 2550 Meadowbrook Road, Benton Harbor, Mich. 49023. In particular, see the Gast “23 Series” compressors shown in the Gast Catalog, Copyright 1998, at pp 12-15. These compressors include an end plate forming a “muffler box” which is constructed so as to have both (1) threaded inlet and outlet ports and (2) sound mufflers. The end plate has some thickness or depth and the ports are located at the top thereof.